Biodiversity recovery following delta-wide measures for flood risk reduction

This paper investigates whether, and if yes to which extend, measures for flood risk reductions such as river restauration contribute to biodiversity recovery.

The biodiversity loss in fluvial ecosystems is alarming, even exceeding the global average of biodiversity decline. River restauration projects mostly aim to reduce flood risk but these measures can also play an important role in enhancing biodiversity. But biodiversity recovery has often been examinated with a very limited number of species in a short time span. Within this study the authors quantified changes in biodiversity over 15 years of river restauration in the Rhine River delta (Netherlands). 179 fluvial floodplains have been evaluated and 137 showed an increase in biodiversity.

Unique to this assessment is the relatively long time span and the coverage of an entire active river delta. The measures carried out led to a flood stage decreased (mean −24 cm) and on the same time showed an increase in biodiversity, particularly for fast-spreading species. The results provide evidence that biodiversity decline can be reversed by combining flood risk interventions with ecological rehabilitation.